ON INTERCEPT ESTIMATION IN THE SAMPLE SELECTION MODEL
样本选择模型中的截距估计
We provide a proof of the consistency and asymptotic normality of the estimator suggested by Heckman (1990, American Economic Review 80, 313–318) for the intercept of a semiparametrically estimated sample selection model. The estimator is based on “identification at infinity,” which leads to nonstandard convergence rate.